Bracelets, necklaces, belts, straps and similar objects are generally fastened in an adjustable manner in predetermined positions, which allow precise re-positioning, and which the user can adjust via the cooperation of a finger with one hole among a plurality of holes, or by hooking a pin onto a rack, or a similar device. Continuous fastenings which maintain position using friction do not offer the possibility of precise re-positioning.
It is often necessary to have an adjustable length fastening, for example between two predetermined positions, to take account of climatic factors or the morphology or comfort of the user.
CH Patent No 699067 in the name of ELFIX PRODUCTION SA discloses a device for finely adjusting the length of a bracelet integrated in a clasp cover, and comprising a device for indexing in two predefined positions, and which includes spring ball push buttons, which are secured to a transverse bar, connected to one end of the bracelet and arranged to cooperate with pierced holes provided in the clasp cover.
EP Patent No 0 737 427 in the name of THE SWATCH GROUP MANAGEMENT SERVICES AG and CH Patent No 695 656 in the name of WERTHANOR SA disclose adjustable links for watch wristlets or bracelets, wherein adjustment is performed by actuating an unlocking button to change from one length indexing position to another.
FR Patent No 2 670 995 in the name of PERILLAT COLOMB discloses a bar which extends in the longitudinal direction of a bracelet, and whose ends are each engaged in a link portion in predefined indexing positions, either by spring bars, or by studs cooperating with holes provided in the bar. A tool has to be used to change from one position to another. These indexing devices extend transversely and require a significant amount of space. They are also visible and detract from the general attractiveness of the bracelet.
These known devices act transversely, generally require a tool to perform the adjustment, and remain visible.
EP Patent No 2484244 in the name of OMEGA SA discloses an adjustable link for a bracelet, including a first half link and a second half link movable with respect to each other in a longitudinal direction, by the cooperation of guide means and complementary guide means, so as to form together an indissociable assembly by the cooperation of arresting means and complementary arresting means. The first half link includes a finger extending in this direction and includes locking means with substantially radial elastic return with respect to said direction, and which are movable between a folded position and an unfolded position. The second half link includes a channel extending in this direction, which is arranged to allow the passage of the finger in only one of the unfolded or unfolded positions of the locking means. This second half link also includes, in proximity to the channel, complementary locking means for cooperating, in at least one locking position, with the locking means in the other of the unfolded or folded positions of the locking means, and the locking means and complementary locking means define together at least two discrete and remote locking positions in the longitudinal direction.